This invention relates to devices for applying compression to parts of the body for therapeutic reasons.
Compression applied to a body part, such as a limb, is essential for resolving many circulatory disorders. The application of compression at a required level has therapeutic benefits. For example, it restores circulation, relieves swelling, treats pain, heals ulcers, and heals varicose veins. Compression levels often must be adjusted quickly and easily in order to promote healing and prevent complications.
Circulatory disorders are chronic conditions for most patients with swelling of limbs. The application of compression to the limbs either during the day, overnight or both is necessary to relieve the swelling. Different levels of compression are necessary depending on the type and severity of the circulatory disorder and whether a person is lying down or standing up. A therapeutic goal is to apply the proper useful amount of pressure to a body part to maintain circulation. Furthermore, sustained compression at predetermined levels is the optimum therapy. (Callam, M. J. et al., Hazards of compression treatment of the leg: an estimate from Scottish surgeons, British Medical Journal 295(1987); Stemmer, R., Ambulatory elasto-compressive treatment of the lower extremities particularly with elastic stockings, Sonderdruck xe2x80x9cDer Kassenartzxe2x80x9d Mittellungsblatt des Deutschen Kassenarztverbandes (1969); Husni, E. A., xe2x80x9cElastic Support of the Lower Limb, Use and Abusexe2x80x9d).
Elastic and non-elastic compression devices, such as elastic stockings, elastic cloth strip (e.g., xe2x80x9cACExe2x80x9d brand) wraps and bandaging systems, and non-elastic, adjustable garments all provide a range of compression, but none actually have an integral gauge or system whereby compression levels can be measured within a specified range as diurnal changes occur or as the patient changes posture. For example, the pressure required when lying down is less than the pressure required when the patient is ambulatory.
Commercially available elastic stockings with no ability for adjustment are made to various compression levels and sizes based on the circumference of the body part. Thus, a person may need several different stockings with varying compression levels depending on the nature and severity of the disorder and whether they are lying down or standing up. Elastic stockings are difficult to apply and remove, and lose compression over time. Elastic cloth strip wraps and bandaging systems are difficult to apply, have to be totally removed and re-applied to adjust compression levels, and do not indicate a compression level. Circulation can be cut off or other complications may occur if they are not applied properly.
One of the more pernicious dangers of elastic cloth strip wrap and bandaging systems is the possibility of unknowingly creating a reverse compression gradient. Thus, the elastic cloth strip inadvertently might be wrapped about the limb so as to apply more pressure at the proximal end of the limb than at the distal end, creating a xe2x80x9ctourniquet effectxe2x80x9d whereby fluids actually collect in the limb, causing further swelling.
Different diseases require different levels of compression, highlighting the need for a measurable and adjustable compression gradient. A burn victim or someone with both arterial and venous insufficiency may need the bare minimum therapeutic level of consistent compression (so that a therapeutic compromise is reached to allow optimal blood flow and fluid drainage) whereas a patient with lymphedema may require a higher level of consistent compression.
Patients have observed that stockings, wraps and bandaging systems made entirely of elastic materials are uncomfortable. Compression requirements change according to whether the patient is upright or prone. Fully elastic devices deliver an unchanging level of pressure, however, which alternately feels either xe2x80x9ctoo tightxe2x80x9d or xe2x80x9ctoo loosexe2x80x9d to the patient depending on the patient""s position.
Indeed, most of the compression devices currently on the market suffer various other degrees of shortcomings, particularly in difficulty of application and removal, lack of adjustability, loss of compression, and discomfort.
Compression bandages are known that indicate the compression provided by the bandage. These compression bandages provide visual indications of varying amounts of elongation and thus tension. See U.S. Pat. No. 3,613,679 to Bijou for xe2x80x9cElastic Bandage with Tension Indicatorxe2x80x9d and U.S. Pat. No. 5,195,950 to Delannoy for xe2x80x9cCompression Bandage with Calibration Means.xe2x80x9d These patents show compression bandages that have various geometrical forms or markings printed over the whole length of the bandages.
Seton Healthcare Group pic of Oldham, England has sold a xe2x80x9cP.E.C. high compression bandagexe2x80x9d under the trademark xe2x80x9cSETOPRESSxe2x80x9d for the treatment of varicose ulcers and associated conditions that has xe2x80x9cvisual guidesxe2x80x9d indelibly printed on both sides of an elastic bandage to ensure correct application resulting in either high or medium compression. These visual guides are colored rectangles, brown for xe2x80x9chighxe2x80x9d compression and green for xe2x80x9cmediumxe2x80x9d compression. When the bandage is stretched the rectangles become squares. The brown rectangles are longer than the green rectangles crosswise or in the direction perpendicular to the longitudinal extension of the bandage. The bandage must be stretched more for the brown rectangles to become squares and therefore brown squares indicate a higher degree of tension in the bandage due to greater elongation. A table is provided in the accompanying instructions to correlate the extension of the bandage (as indicated by the rectangle/square visual guides), when the bandage is wound spirally with a 50% overlap, to the compression in the wrapped limb for different limb circumferences.
Another approach to providing predetermined compression to a limb that uses colored indicia is disclosed in Smith and Nephew""s PLC""s published international application number WO 97/39709 (international application no. PCT/GB97/01078) for a xe2x80x9cCompression Device.xe2x80x9d
Patients and medical technicians should be able to accurately and reliably set a specific desired compression or compression gradient and be able to easily maintain and adjust the compression or compression gradient as necessary. None of the current devices have these properties.
Compression devices therefore are needed that have measuring systems for predicting and measuring the compression or compression gradient when users wear the devices. A need thus exists for a compression device with a system for measuring the compression provided by the device so that the device can be easily and rapidly adjusted to provide a correct and sustained compression or compression gradient and to quickly change the compression and compression gradient. A need also exists for compression devices with compression measurement systems that are easy to apply to and remove from parts of the body that have varying circumference and that are comfortable to wear throughout the day and in different postures.
Sustained compression is key to proper treatment. It is often a problem with compression devices that the applied compression goes down over time or with fluctuations in limb volume. The ability to measure compression and adjust easily enables compression to be maintained at an appropriate level.
The compression device according to the invention provides a band for applying compression to an object such as a part of the body, and a system for measuring the compression provided by the device so that a prescribed or desired compression can be easily applied to the body part and quickly adjusted as necessary for a therapeutic purpose such as to relieve swelling caused by a circulatory disorder or trauma. As used in this specification, xe2x80x9cbandxe2x80x9d means any device that encircles or surrounds at least a portion of an object such as a body part and can include in its meaning a strap, wrap, sleeve or garment, or any combination of such devices.
The compression measuring, application, and adjustment system provided by the invention are based upon the known elastic or stretch properties of an elastic fabric or material comprising the device""s bands, straps, wraps, sleeve or garment. The elastic component of the compression device will stretch when placed under tension. The measure of the stretch along an elastic axis of the elastic component is correlated to the tension along the elastic axis. The compression provided by the device is proportional to the tension when the elastic axis has a component parallel to the circumference of the body part or limb (that is, the elastic axis and thus the tension have components perpendicular to the longitudinal direction of the body part or limb). The compression is inversely proportional to the circumference of the body part. The system of the invention measures the stretch and provides the corresponding compression as a function of the previously measured circumference of the body part.
The system may be a combination of indicia printed at intervals on the device and a separate scale or measuring device such as a card for measuring the separation of the indicia and making the conversion of stretch to compression as a function of circumference.
In another embodiment of the invention, the system comprises scales printed on the device. The position of a free end of the device with respect to the scales varies with stretch and indicates the tension in the device and thus the compression for a given circumference. The scales in this embodiment may include markings for measuring the circumference of the body part so that the correct scale is chosen for reading the compression.
Pockets may be attached to the free ends of bands or sub-bands that are sized to permit the insertion of one or more fingers. This will allow the user to pull or push the free ends of the bands or sub-bands in order to tighten them and thus apply tension to a compression device so that it will provide the appropriate compression to the underlying body part.
An object of the present invention therefore is to provide compression devices with systems for allowing the user to accurately and reliably predict and measure compression levels.
Another object of the present invention therefore is to provide compression devices with systems for allowing the user to accurately and reliably apply pre-selected compression levels.
Yet another object of the present invention is to provide compression devices with systems for allowing the user to quickly change the compression levels being applied by the devices to new compression levels.
Another object of the present invention is to provide compression devices with systems that allow the user to accurately and conveniently change the compression levels being applied by the devices to the different compression levels required by different postures.
Still another object of the present invention is to provide compression devices with systems for allowing the user to quickly change the compression levels being applied by a device without having to remove the device from the body part or limb.
A further object of the present invention is to provide compression devices with systems for measuring compression so that a consistent tension will be present in all parts of the device in order to create an automatic distal-proximal compression gradient along the body part.
A still further object of the invention is to provide compression devices that are comfortable to wear.
Another object of the invention is to provide compression devices that are easily applied to and removed from parts of the body.
Yet another object of the invention is to provide compression devices that contain integral circumference measuring systems.
Still another object of the invention is to provide compression devices that are easy to tighten when setting the compression to be applied by the devices.
Yet another object of the invention is to provide compression devices that provide effective treatment.